Electrically-operated air-brake system.



No. 897,218." PATENTED AUG. 25, 1908.

- f- W. o. MAYO. y BLBGTRIGALLY OPERATBD AIR BRAKE SYSTEM.

APLIGATION FILBj) NOV. 22, 1907.

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No. 897,213. PATENTED AUG. 25., 419.08.

. W. o. MAo. ELEGTRIGALLY OPERATED AIR BRAKE SYSTEM.

'APPLICATION FILED NOV. 22, 1907.

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No. 897,218.' PATENTED AUG. 25; 1908.

. W. o. MAYO. BLBGTRIGALLY OPERATBD AIR BRAKBSYSTBM.

A1PLIOA'1'ION FILED NOV. 22, 1907.

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No. 897,218. EATENTED AUG. 25, 1808.

' W. 0. MAYO.

ELEGTEIGALL-Y OEEEATED AIE EEAKE SYSTEM.

APPLICATION FILED Nov. z2 1807.

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J9] Y- l 1.93 2f -u j@ i@ w ff z /f 1% f I 'Y f @L '8AM No. 897,218. PATENTED AUG.25,1908.

. W. c. MAYO.

BLBGTRIGALLY OPBRATED AIR BRAKE SYSTEM.

APPLICATION FILED nomas 1 o 9 7 a SHEETS-SHEET 7.

110.897,'218. PATBNTBD AUG. 25, 190s.

. W. G.,MAY0.

ELBCTRIGALLY OPERATED AIRBRAKE SYSTEM.

APrLIoATIoN FILED Nov. 2z, 1907.

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UNITED sTATEsj PATEN OFFICE.

WILLIAM o. MAYO, oF ELE-iso, TEx'As, AssIeNoE OF ONE-THIRD To GEORGE E. BEIGGS, or BARsTOw,y TExAs, AND eNE-THIED To WILLIAM c. MAYO AND ONE-THIRD To JOHN IIOULEIIAN, or EL IAso, TExAs.

ELECTRICALLY-OPERATED AIR-BRAKE SYSTEM.

Specification of Letters Patent.

Patented Aug. 25, 1908.

Application filed November 22, 1907. Serial No. 403,361.

To allwhom it may concern:

Be it lknown that I, WILLIAM C. MAYO, a citizen of the United States, residing at El Paso, in the county of El Paso and State of Texas, have invented a new and useful Electrically-O erated Air-Brake System, of which the ollowing is a specification.

This invention has reference to improvements in electrically operated air brake systems and it comprises both a means for insuring a constantsupply of compressed air and also an electrically operated triple for the control of the air to Operate the brakes.

While the present invention is of general applicability and may be used on either steam or electric roads, it is designed more particularly as a part of a gasolene -motor traction system wherein each car is a unit, and the cars may therefore be used severally, or collectively in the form of a train.

` For the better understandimg` of the present invention, it is deemed best to briefly consider the ordinary air brake systems in commonuse. In the ordinary system, the usual pressures are seventy pounds per square inch for the train pipe and ninety pounds per square inch for the main reservoir pressure. rihis gives an excess of twenty pounds pressure for recharging the auxiliaries under each car after a brake application, that is, this excess pressure first places the triple piston in Alecting friction which amounts to but a few ounces.

The movement of the triple piston and its attendant graduating valve opens a port which allows the auxiliary reservoir to exhaust into the brake cylinder. When,

however, the auxiliary pressure is reduced to sixty-three pounds, the triple piston will stop' its movement while holding the port open to the brake cylinder. The auxiliary pressure then further falls by continuing the exhaust into the brake cylinder until it is below sixtythree pounds, and then the train pipe pressure, though only sixty-three pounds, will move the triple piston back so as to lap the port from the auxiliary reservoir 'to the brake cylinder by the closing of the graduating valve. In this position, all other ports are also lapped or closed. Under these circumstances, there is now, say, a little over sixty-two pounds pressure in the auxiliary.

lf the main reservoir contained only the train pressure of seventy-pounds and not the vfr-.ll pressure of ninety pounds, then when the train pipe is connected to the Inain reservoir to recharge the train line, itis evident that to establish seventy Apounds pressure throughout the train vmore than seventy pounds must be in the main reservoir, since very little air flowing from the main reservoir will cause a reduction in its pressure, and this reduction is, in practice,faster, depending on the length of the train, than the pump can replace, and the train line would equalize with the main reservoir pressure to a point somewhere below seventy pounds. Now, since under the conditions assumed, the auxiliary is still sixty-twopounds, then in a long train the train pipe pressure may equalize with the main reservoir pressure at or below the auxiliary pressure, and hence the triple piston will not be driven back except slowly as the pump brings lup the pressure. Hence, the brakes will come off slowly or not at all, and the triple will remain lapped until the pump has raised' the pressure suffi-A ciently, and the train is brought to a standstill until this is accomplished. ATo overcomethis difficulty is the reason for the twenty pounds excess pressure in the main reservoir. Now, while twenty pounds ex-` cess pressure is usually suflicient, since a service application or the sum of the respective reductions of more than one service application is always less than twenty pounds, because twenty pounds train pipe reduction will place the triples in emergency, still this is not always the case, although, of course, after recharging the train pipe, the main reservoir pressure is again brought up by the pump to ninety pounds.

In steam railway practice, where the stops are infrequent, the pump, even with a long train, has usually plenty of time to restore the main reservoir pressure, but in systems where the stops are frequent, it is necessary to make other provision.

The general system of which the present invention is a part is designed for city, subur* ban and interstate trallie, and provision must therefore be made for frequent stops or applications of the brakes, aswell as for the application of brakes at longer intervals. Now, air brakes are, used on city cars or trains, but this means that the pumps, then electrically driven, are cutting in and out at nearly every stop, because the excess pressure used is only the commonly employed twenty pounds excess, which answers very well for the infrequent brake applications of steam railways. In city trains, this small excess of pressure means excessive wear on the pump equipment, which in practice is generally the case, or excessive size of main reservoir.

New, it is the object of one portion of my invention to obviate the objectionable features due to the use of the ordinary 4air brake equipments on cars or trains where the stops are frequent, and this part of my invention comprises means whereby I am enabled to produce and maintain a much higher main reservoir pressure and consequently a smaller main reservoir, and also produce less wear on the pump, since, after the pump has established a high main reservoir pressure, it can remain out of action for some time before it must again come into service. I may state that generally I use one hundred and fifty pounds main reservoir pressure, but this pressure, though always high compared with the pressure ordinarily used, may be varied in accordance with the conditions to be met. Of course there would be greater leakage with one hundred and fifty pounds main reservoir pressure if used with the apparatus commonly employed with the main reservoir on the locomotive or leading ear, and hose connections between the cars. This I obviate by placing a main reservoir under each car, thus doing away with the heavy and expensive hose connections which would be necessary in the ordinary system. Again, the heavier pressure means a stronger pump, but 4this adds but little to ythe cost of the pump, since it` requires little, if any, more machine work on the pump, but only more metal to withstand the heavier pressure.

The triple valve referred to is what is known as the simple triple, and the operation described is known as automatic air. There is, however, in use an improved triple known as the quick action triple, which is identical with the ordinary triple in all its operations, except in the matter of the einer gency application. The simple triple does not set the brakes at emergency harder than a full service application, but it sets them quicker. Also, under all circumstances, no air is used except that from the auxiliary ser/,21s

reservoir for the brake cylinder to set the brakes, and all reductions of train pipe pressure are made at the'engine-mans station by the usual valve there located. This is true in respect to the quick action triple in service applications. I-Iowever, when an e mergen ey reduction of train pipe pressure of twenty pounds or more is made, the reduction is effected first near the enginemans valve in. the locomotive, or head motor car. As the quick action triple on the head car goes into emergency, it opens a valve admitting train pipe pressure into the brake cylinder Vl'irst and then auxiliary pressure. This causes a local reduction of train pipe pressure regardless of the enginemans valve. This, of course, throws the quick action triple on. the next car into en'iergency, which, in turn, sets that of the, third car, and so on, so that the quick action triple not only sets the brakes quicker in emergency than in the service application, but, unlike the simple triple, it sets them harder. There is still another equipment known as the high speed brake, but it need. not be here considered..

Quick action triples are used on high speed trains because they not only set the brakes quicker and. harder and more nearly together than the simple triple, but if the engineman makes a reduction of pressure sul'licient to set the 'lirst quick action triple to emergency, the whole train will go into emergency, even though the initial reduction be but twenty pounds. New, even though it is against the enginemans instructions to use the emergency except in times of necessity, and then he must place his valve on emergency and let it stay there and must not lap on cmergency, still orders and instructions are not always obeyed.. New, if the engineman makes an emergency application, and. then. laps his valve quickly on the simple triple, then, if the train pipe be a long one, the rear cars will not feel the application. until after an appreciable time, and. the air once started in a long train will, is most cases, by its surge to the front of the train, kick off the head. brakes. Thus the head brakes lirst go on and the rear cars run ahead and the train bunches,7 since the unbraked, or but slightly braked, rear cars take up the slack with heavy blows against the head. cars. Then, as the applicationl is felt on the rear cars, and, as sometimes happens, the brakes kick7 from the headv cars, the slack travels toward the rear y and the train stretches This, of course, is destructive to the rolling stock and to the contents of the ears. The quick acting brake does not cure this defect, since thereis still some runniiig ahead of the rear of train, for, even in the quick acting brake, there is a time element, though small, between the application of the brakes on the head and rear cars.

New, it is the object ol the second. part ol'V there bein semis my invention to overcome these objectionable features, and 1 do this by providing an electric triple valve so constructed and operated as to simultaneously apply all the brakes equally and make any application of the brakes, regardless of the slowness and quickness of the enginemanin making the application, practically instantaneous. This second part of my invention comprises certain instrumentalities by means of which this object is accomplished, and these instrumentalities, their structure and operation, will appear from the detailed description thereof which will follow in due course.

Having thus set forth the conditions giving ing rise to the present invention, l will now proceed to describe the invention in detail, iaving reference to the accompanying drawings forming part of this specification, and in which drawings,

Figure 1 is a side elevation, with'parts in section and other parts broken away, of the pump and governor used in my air brake system. Fig. 2 is an end elevation of the same structure, with parts in section and other parts broken away. Figs. 3 an-d 4 are sections, at right angles one to the other, of the governor mechanism. Fig. 5 is a longitudinal section through the electrically operated triple valve forming part of my invention. Fig. 6is a cross section at right angles to the section of Fig. 5, with parts shown in elevation. Fig. 7 is a diagram of the electric circuit. Figs. 8, 9, 10 and 11 are views of portions of the triple valve on a larger scale. Fig. 12 is an end view of the casing of the triple with parts broken away. Fig. 13 is a section through the casing with parts removed from the interior thereof. Figs. 14 and 15 are views of the brake cylinder and parts coperating therewith. Fig. 16 is a detail view of a portion of the crank-shaft of the pump.

Referring first to Figs. 1, 2, 3 and 4, there is shown a casting consisting of a base plate 1 from which rise two cylinders 2, 3 side by side, and the base plate may have formed on it a number of studs 4 projecting in a direction o posite to the direction of projection of the cy inders. These studs are formed with through openings 5 for the passage of bolts or screws 6 by means of whichthe structure is secured in place upon a suitable support.

The tops or outer ends of the cylinders have cast on them two series of brackets l7, three brackets on each side with the centra brackets serving to connect or bind the free ends of the cylinders together. These brackets carry pedestals 8 cast in one piece with the connecting yoke 9, there being three castings composed each of two pedestals and the yoke 9. Each of the yokes 9 is suitably formed to constitute one-half of a journal bearing, the other half of which is in the form of .a cap plate 10. However, in the structure shown in the drawings, thel cap plate 10 is applied to the pedestal structure on the cylinder side thereof for a purpose which will presently appear. The pedestals are suitably recessed, as shown at 11, to receive bolts or screws 12 securing the said pedestals to the brackets 7. The bearings formed by the yokes 9 and cap plate 10 receive a crank shaft 13 having cranks 1,4 diametrically disposed, and these cranks each receive a pitman 15 by means of the usual journal bearmus.

hWithin the cylinder there is a piston 16 of the'usual trunk type provided with a suitable number of packing rings 17. The piston has diametrically disposed lugs 1S constituting supports for a pin 19 passing through a journal bearing in the corresponding end of the pitman 15 of the respective piston.

The two cylinders, with their pistons and pitmen and the crank shaft, constitute a simple type of duplex acting pump, in this case an airpump, and the parts are designed both in size and speed of operation to supply air as needed up to and to maintain within a suitable reservoir a pressure of one hundred and iifty pounds per square inch. Since the inlet and outlet ports and valves of the pump are, or may be, of ordinary construction, only the exterior thereof is shown in the drawings at 20 and 21, respectively, the inlet valve structure 2O being provided with a screened induction opening 22, and the outlet valve structure communicates with a pipe or conduit 23 which is assumed to lead to a suitable reservoir, the latter, however, not being shown in the drawings, it being of the type usually employed in air brake systems.

The crank shaft 13 is extended at one end beyond its bearings and there has keyed to it a gear Wheel 24, which gear wheel is in mesh with a gear pinion 25 on a shaft 26, which shaft may be the power shaft of a suitable prime mover, such, for instance, as the explosive engine heretofore referred to. The pinion 25 is mounted to turn freely upon the shaft 26 and `for this purpose is provided with a bushing 27 of bronze or Babbitt metal, or other suitable material. Now, in order to prevent the pinion from moving longitudinally of the shaft 26, the gear teeth of the wheel 24 and pinion 425 are made of the herring-bone type, which type of gear teeth also provides a smooth running intermesh between the gear and pinion.

On one side of the pinion 25 is formed a hub 28 terminating in an annular series of teeth 29 having inclined faces and an abrupt shoulder with the junction point between the inclined face of one tooth and the base of the preceding tooth formed with a notch or depression 30. The hub 28 with the teeth 29 constitutes one member of a clutch couple,

the other member of which is formed of a similar hub 31 having` teeth 32 with notches 33 like the notches 30, and this hub 3]. is formed on a collar 34 mounted on the shaft 26, but secured thereto for rotation therewith ly a spline or key 35, although this collar, with its hub 3], is capable of longitudinal movement on said shaft 26. The collar 34 has a central peripheral groove 36 the sides of which convergetoward the axis of the shaft. Within the groove 36 are two frustoconical rollers 37 disposed on dianictrically opposite sides of the axis of the collar and carried at the ends of a fork 33 formed on the end of the lever arm39. The free ends ofthe fork33 are each formed in to a boss 40 in which latter there is secured a pin 41` projecting radially inward and constituting a liournal support for the respective roller 37. The converging walls of the groove 36 coact with the ffusto-conical periphery of each roller 37 to maintain the latter upon its journal pin 4] so no special fastening means is required for this purpose.

Fast upon the base plate l., or to a suitable crtension thereof is a bracket 42 terminating in a circular head 43 from one face of which there projects an annular flange 44 and a eentral stud 45. On the opposite side of the head 43 from that containing the flange 44 rfid stud 45 there is formed a cylinder 46 extending diametrically across the head 43.

Secured to the head 43 by means of stud bolts 47, or otherwise, is a casing 48 having a :flange for the reception of the bolts 47. This f asing is of sufficient internal diameter at one end to receive the annular fiange 44, and this portion of the casing terminates in a shoulder 49 between which and the end of the flange 44 there is confined a diaphragm .5() preferably of rubber but which may be made of any other suitable material. Beyond the shoulder 4), which is an annular shoulder, the easing 43 is of less internal diameter, and this portion of the casing terminates in another annular shoulder 51 forming a seat for a bearing ring 52 of brass or bronze, or other suitable material. Beyond the shoulder 51, the casing may be tapered, as shown, or be otherwise shaped, and terminates in a head 53 through which is a central perforation for the passage of a piston. rod 54. @n the exterior of the casing there is formed a bracket 55 terminating in ears 56 between which engage bosses `57 formed on opposite sides of the lever 39. This lever is pivotally supported between the ears 56 by a pivot pin 58 having one end of polygonal shape, as shown at 5), and the other end reduced and threaded, as shown at 60, to be seated in a nut formed in one of the ears 56. The structure just described with reference to the pin 53 is shown in connection. with the piston rod 54, as illustrated in F ig. 4, where it will be seen that the piston rod terminates in two ears 61 like the ears 56, and the relation of the pin 53 to these ears is here most clearly shown. lt will be understood that wherever the structure as a whole calls for the use of pivot pins, such Apivot pins are preferred. On that end of the piston rod 54 within the casing 43 there is secured a piston 62 by shouldering and tapering the end of the piston rod and inserting it in a tapered seat in the piston and there securing it by means of a screw 63 he head. of which is countersunk into the further face of the piston. The diameter of the pistou is such that it will slide freely, yet snugly, in the bearing ring 52, and this bearing ring is made removable so that when worn it may be replaced, Nithin the casing 4S, between the head 53 and the )iston 62 the )iston rod is surrounded by a spring 64 tending to urge the piston 62 against the diaphragm 5() and the latter into engagement with. the stud 45, the edges of which are slightly rounded to avoid cutting this (.liaphragm.

The tendency of the spring 64 is to move the lever 39 in a direction to cause the fork 33 to travel toward the left, as viewed in Fig. 1, and' a force acting upon the diaphragm 50, in opposition to the spring 64, will tend to move the fork 3S toward the right as viewed in Fig. l. When either of these forces is exerted, the collar v34 constituting one member of the clutch couple, participates in the movements caused by these forces. The parts are so designed that the movement of the piston. rod 54 in either direction is sufficient to cause the engagement or disengagement of the teeth 2S) and 32, so that, assuming that the spring 64 is active, then the clutch members are engaged and power is transmitted from the shaft 26 through the clutch to the pinion 25, and from thence to the gear wheel 24 and the pump pistons are then set in motion. )When by a force applied to the diaphragm 5() in oppositioi'i. to the spring 64, the latter is overpowered, then the clutch members arc disengaged. and, power no longer being transmitted to the pump pistons, the latter are stopped.

Within the cylinder 46, there is a piston 65 provided with a suitable packing ring 66. This piston is fast upon a piston rod 67 near one end thereof. The piston rod beyond the piston is formed with an annular enlz'trgemcnt or head. 68 having the face remote from the piston shaped to engage a flat valve seat, as will presently appear. In line with. the cylinder 46, that is central with the bore thereof there is formed through the bracket 42 a conduit or passageway 69 and, at the point of connection of this passageway 6) with the interior of the cylinder, this passageway is counter-bored, as shown at 70, to receive a stem. 7l projecting from the flat face of the head 68 as a continuation of the piston rod 67. Surrounding the bore of the cylinder 46 at the end entered by the vconduit 69 is an annular lgroove 72 into which is sprung a rubber or similar washer 73 `the conduit 69 formedopen, and this open end is closed by a screw plug 74 formed with a hexagonal nut 75 for the application of a wrench and with a flange 76 between which and the end walls of the cylinder is introduced packing 77. The plug 74 has a central bore 78 extending for a distance into its body from the inner end to receive the corresponding end of the piston rod 67, this end of the piston rod being formed conical to constitute a valve 79, and the inner end of the bore 78 is shaped to form a seat for the valve 79. Leading from the inner end of the bore 78 is a passageway 80 terminating and opening at the side of the plug into an annular groove surrounding the plug 74, and also leading from the bore 78 at a point above the valve seat is another passage 81 opening into the cylinder at the inner end of the plug. Leading from the annular groove into which o ens the passageway 80'at the side of the p ug is another passage or conduit 82 in the lead 43, which passageway leads to and through the stud 45, and terminates at the center thereof where it opens into the chamber 83 formed between the innerv face of the head 43 and the diaphragm 50 and circumscribed by the flange 44. This chamber is also in communication with vthe interior of the cylinder 46 above the piston 65 by way `of a port 84.

Between the piston 65 and the plug 74 the piston rod 67 is surrounded by a helical spring 85, and that portion of the interior of l the cylinder 46 housing this spring .85 is in communication with the external air through a permanent port 86. brought into direct metallic contact with the basey 1, or the extension therefrom, to insure a firm seat,'and the conduit or passage 69 is then in coincidence with another passage 87 in communication through the base 1 or extension thereof with the conduit 23 leading to the reservoir. Now, in order to insure an air tight joint, the bracket is counterbored around the conduit 69, and, if need be, the base 1 is counterbored around the passage 87, so as to receive a soft rubber washer 88 having a central passage normally of greater diameter than the diameter of the passages 69 and 87, and the normal thickness of this washer is greater than the depth of the countersink in the bracket 42, or the combined depth of the countersinks in theV meetingv The bracket 42 is' faces of the bracket 42 and base 1 when bothl are countersunk. The diameter of the washer is such as to snugly lit these countersinks. Now, when the bracket 42 and basel are broughtk together, the rubber washer 88 is compressed because it is ofgreater thickness than the depths of the countersinks, and therefore when compressed it must expand in the direction of least resistance, which is toward the central perforation since the walls of the countersinks prevent this washer from expanding outwardly. The central perforation of the washer is, however, made larger than the diameter of the passageway 69 or 87, so that when the washer is compressed, the reduction in diameterof the central perforation, due to the compression of the washer, is insufficient to throttle either passage. l resist internal pressure, while permitting adjoining structures to be brought into direct metallic contact. A similar packing to the one just described is introduced between the Casing 62 and. the head 43, as indicated at 89, while the packing 77 ,before referred to, may be similar to the packing 88.

It is to be understood that ,throughout the structure forming the subject matter of the present invention, I prefer to use packing in the manner set forth in the reference to packing 88 wherever internal pressure will act upon such packing, and such a structure spring 85 holds the valve 68 firmly against.

the seat 73 with the valve end 79 away from its seat in the plug 74. The spring 64 holds the piston 62 with the diaphragm 50 in firm engagement with the face of the stud 45; Under these conditions, the passageway 69 is closed by the valve 68, and the passage'- way 82 is closed by the diaphragm, but this passageway 82 is open to the external air through the passages 80 and 81 and the port 86. NVith the parts in the position assumed, the clutch members are in engagement and consequently the pumps are at work. Incidentally, the stud 45 acts as a stop for the piston rod 54 and, consequently, limits the movement of the clutch members toward each other, preventing the teeth from pressing with undue force upon each other.

For the purposes ofthis description, let it be assumed that the area of the piston 65 is one square inch and that the spring 85 exerts a pressure of ninety pounds., then, this spring will yield when the pressure upon the other side of the piston 65 exceeds ninety pounds. As has already been stated, the reservoir pressure to be maintained is one hundred and fifty pounds per square inch, therefore, the end 71 of the piston rod 67, which end 71 is seated in the counterbore of the passage `69 in constant communication with the reservoir, must have an area so much smaller th an a square inch as the reservoir pressure is proportionately larger than the power of the spring 85. So, under the conditions assumed, an end area of three-fifths of a square inch of the stem 71 will cause a reservoir pressure of one hundred and iifty pounds to the square inch to balance the spring 85. New, a slight increase of reservoir pressure will force back the piston rod and open thevalve 68, so that air escapes into the cylinder 46 above the piston 65, and also reaches the chamber 83 through the port 84. New, since the valve 68 is opening under a pressure of one hundred and tty pounds per square inch, it will be seen that the upper end of the cylinder and the chamber 83 are almost instantly iilled. As soon as the pressure has reached ninety pounds above the piston 65, the latter is moved against the tension of the spring 85, and the valve 68 is opened wide, so that with a Jfull pressure of one hundred and fifty pounds, there is an excess of sixty pounds acting on the piston 68. This results in the immediate closure ol the valve 79. But, in the meantime, pressure has been accumulating in the chamber 83 which is in constant communication with the upper end of the cylinder 46 through the port 84, and this pressure is being exerted upon the diaphragm 50 and through it upon the piston 62. This pressure, however, is resisted by the spring 64 which is adjusted to resist an air pressure of eighty pounds per square inch before yielding. New, let it be assumed for the purposes el the present description that the area of the piston 62 is one square inch, then the spring 64 presents an absolute resisting force ot eighty pounds. But since the diaphragm 5() is in contact with the stud 45, then the effective area under the influence of the accumulating pressure in the chamber 83 is reduced by an amount equal to the area of the face of the stud 45. Let it be supposed that the face of the stud covers two-ninths of a square inch, then the e'l'ieetive area of the active end of the piston 62 is but seven-ninths of a square inch, so that when the pressure in the chamber S3 is ninety pounds per square inch, then there is an absolute pressure upon the piston 62 in opposition to the spring 64 of but seventy pounds. Consequently, when there has accumulated above the piston 65 a pressure sufficient to overcome the spring 85, the torce of the spring 64 is still suHicient to maintain the diaphragm against the face of the stud 45, and it is not until the pressure in the chamber 83 exceeds one hundred pounds per square inch, say, one hundred and three to one hundred and four pounds per square inch, that the pressure upon the effective area of the piston 62 through the diaphragm 50 is su'tlicient to overcome the absolute pressure of the spring 64, and thus cause the piston and diaphragm to move away from the stud. 45. But as soon as the piston moves away 'from and so uncovers the liace of the stud 45, the `lull area of the piston at once becomes el'l'ective, and, under the assumption that the area of this piston is one square inch, then the spring 64 is opposed by a pressure ol", say, one hundred and three pounds, or twenty-three pounds in excess of its power, and this pressure is constantly increasing up to one hundred and Vlility pounds, or seventy pounds in excess ot the spring. This results in a quick movement of the piston to disengage the clutch coupling the power sha'lt to the pump. However, the more sluggish action of the piston 62 has given time lier the movement ol" the piston 65 against the action oli the spring S5, and the valve 79 has become seated in the plug 74, so that the passages P() and $2 are closed to the external air. .Since the spring 64 has a 'lorce of eighty pounds, the pump will remain inactive so long as the pressure in the chamber SS exceeds eighty pounds.

New, let it be assumed that the air in the 'reservoir has Abeen used for braking purposes, and tor other purposes in the system ol which the present invention is a part until the air pressure in the reservoir is reduced to ninety pounds. Under these conditions, there is still ten pounds excess pressure against the spring 64, thereby keeping' the pump crit out, while the piston 65 is ready to move under the action of the spring S5, because the air pressure and spring pressure are now balanced. Suppose, new, that the air pressure is again reduced to slightly below ninety pounds. The spring 85 tends .now to close the valve 68, and the parts are so adjusted that the valve 68 is nearly closed by the time the valve 79 opens to permit air to escape l'roim the passage S() through the passage Si and out throughtheport. Undertheseconditions, that portion of the cylinder 46 above the piston 65 and also the chamber are both in coi'mnunication with the external air through the passages 80,81 and S2 and port 86. Now,

` the passages 80, 8]. and S2 and the port S6 are comparatively large, so that the air exhausts rapidly, while little escapes by the valve 68, since this last-named. valve is very nearly closed and the exhaustpassages lor the air are so large that the pressure lalls rapidly in the upper end of the cylinder 4.6 and in the chamber 43, in spite ol the liaet that air from the main reservoir is escaping by the 'valve 68. The decreased pressure above the piston 65, together with an accumulation ol pressure on the spring side of the piston, heeause the port 86 is made slightly smaller inV area than the passages 80, S1 and 82, will aecelerate movement of the piston under the impulse ol the spring 85. The parts may be so proportioned that the exhaust through the port 86 will be slow enough te permit the pressures on opposite sides of the piston 65 to reach nearly the same values, and the piston is therefore under practically the full action of the spring 85. Furthermore, it takes less pressure to continue the motion of the piston than to start it. It will thus be seen that movement of the piston 65 to closed position is practically instantaneous,

The capacity of the cylinder 46 above the piston 65, and also the capacity of the chamber 83, is small, therefore, the opening of the valve 68 is also small, and since the pressure of the spring 85 will somewhat compress the packing or gasket 73 when the valve 79 is fully open, the resiliency of this rubber gasket 73 will cause it to slightly expand and follow up the valve 68 for a short distance before the said valve actually leaves it when moving against the action of the spring 85. Since, in any event, the travel of the valve is very short, the expansion of the rubber gas*- ket will'be such that the valve 68 will close with the valve 79 but partly open, and the compression of thegasket 73 will then permit the full opening of the valve 79. Now, as the piston 6`5 starts to close the valve 68, when the pressure in the reservoir is but a fraction below ninety pounds per square inch, and as the pressure in the chamber 83 must be reduced to eighty pounds per square inch before the p-iston 52 will move under the impulse of the spring 64, and, since the valve 68 closes almost instantly, it follows, therefore, that the valve 68 will be tightly closed efore the air pressure in the chamber 83 is reduced to eighty pounds per square inch.

Now, an air pressure reduction of three or four pounds below ninety pounds will cause the certain closure of the valve 68, so that there must still be a reduction in pressure of five or six pounds more through the exhaust port 86 before the piston 62v will move. As

- soon as the valve 68 becomes seated, the

back pressure from the reservoir is exerted only on the end of the stem 71, and as this stem is only about three-fifths the area of the piston 65, the spring 85 overbalances the reservoir pressure at a ratio of live to three, thus firmly seating the valve 68 quickly and surely without chatter'. In the meantime the air pressure in the chamber 83 is reduced by the escape of air to the port 86 and the spring 64 becomes active to move the piston 62 until the diaphragm 50 is seated on the stud 45 and the pumps are put into action and will remain in action until the reservoir pressure reaches one hundred and fifty pounds, when the resistance of the spring 85 is overcome and the operations described are repeated.

It will be apparent from the foregoing that the governor is quick acting with a large -effective pressure tov hold the clutch Vin engagement and with a large force for disenactive position by the force of the spring 64 which is eighty pounds, and is moved out of engagement by the reservoir pressure of one hundred and fifty pounds from which must be taken the eighty pounds pressure necessary to compress the spring 64, thus leaving an effective pressure of seventy pounds to disengage the clutch. Thus the movements of the governor are quick and positive, preventing broken or injured teeth at the clutch, and this latter contingency is further avoided by the recesses 30 and 33, at the bases of the teeth.

It is quite evident with the style of clutch illustrated, seventy or eighty pounds pressure would not be needed, or, at anyrate, not more pressure would be needed. The'governor is therefore made quite small, and may be materially smaller in proportion than shown in the drawings.

The movement of the rubber diaphragm 5() is necessarily limited and the stroke of the piston 62 is correspondingly very shortl Now, if the movement of the clutch members toward and from each other is considerable, then the ratio between the two arms of the lever 38 must be correspondingly large, and the governor must be proportioned to meet the conditions present. Of course, the inclusionin this application of the toothed clutch does not preclude the use of a friction clutch of any suitable type.

Referring now to Figs. 5 to 13, both i11- clusive, there is shown an electric triple designed to operate on the straight air system primarily, but including means whereby the triple may be adapted to the automatic air system, so that the controlling power may be coupled up with cars equipped with the straight air system of brakes, or with cars equipped with brakes operated on the automatic air system, or with both. The casting of the triple is made in two parts, 90, 91, for convenience of manufacture and accessibility of the interior of the casting for machining the parts and for the assembling of the structure. These two castings are provided with matching ears 92 through which pass bolts or screws 93 for securing the two parts together. The meeting parts of the two castings 90 and 91 are provided with packing rings 94 similar to the packing rings 88 and 89 described with reference to Fig. 4. In fact, wherever packing is required between fixed inetal surfaces in the triple valve, such packing will be used, but this does not preclude the use of ordinary packing rings in the manner commonly employed. Within the casting 90 there is formed a cylinder or cylindrical chamber 95 one end of which is closed by the other. portion 91 of the casing. there is a short trunk piston 96 shown in section in Fig. 5 and in elevation in Fig. 6.

gaging the clutch. The clutch is held in its l The piston 96 isprovided with one or more 1n the cylinder 95 packing rings 97 of suitable type, but one being shown in the drawing. The periphery of the piston is turned down about midway of the length of the piston to form two beariag portions 98 and 99, the bearing portion 98 carrying the packing 97.

The piston is provided with a hub 100 suitably tapped to receive the threaded end of a stout tube 101 open at each end but closed near the center by a diaphragm 102 which may be made integral with the tube. This tube is thereby divided into two cylindrical chambers 103 and. 104, the chamber 104 being slightly greater in diameter than the chamber 103. Within the chamber 103 is a helical spring 105 of sufficient strength for a purpose which will hereinafter appear. Extendingthrough the centrally bored and true hole in the piston 96 is a plain headed pin 106 engaged. by and forced outwardly by the spring 105. This pin fits snugly in the hole in the piston, but at the same time is free to be moved to put thc spring 105 under compression, which happens when the piston is moved into the cylinder 95 to a sufficient extent to bring the free end of the pin 106 into contact with the back wall 107 of the cylinder 95. Contained within the other chamber 104 is a graduating valve 108 which slips snugly but freely through a screw plug 109 entering the open end of and thereby closing the chamber 104. The graduating valve has its rear end formed with an integral annular flange 110 snugly but freely fitting the interior of the cylindrical chamber 104. This Ilange also prevents the valve 108 from being withdrawn 'from the chamber 104 by engaging the bushing or screw plug 109, which thereby acts as a stop for this valve 108. Furtlrermore, the bushing 109 and the flange 110 coact to guide the valve 108, thus insuring a true traverse of the said valve 108 within the chamber 104. The valve 108 has a central longitudinal bore 111 extending from its rear end to near the front end, and housed. in this bore is a spring 112 abutting at one end against the inner end wall of the bore and at the other end against the diaphragm 102. The tendency of this spring is to con# stantly project the valve 108 out of the chamber 104. The outer end of the valve 108 is formed. with a head 113 of conical shape acting, during a limited and predetermined travel of the piston 96 toward the wall 107 of the cylinder 95, to maintain the service port 114'closed.

Opening into and concentric with the cylinder 95 is another cylinder 115 formed in the casing 91. This cylinder 115 is somewhat longer and is of less diameter than the cylinder 95. The chamber 104 and valve 108 and parts coacting therewith is contained within the cylinder 115, which cyl inder in one cycle of o}i eration .s, together with that part of the cylinder 95 on the correspending part of the piston 96 constitute the auxiliary reservoir pressure chamber. This cylinder or chamber 115 and the eoactin part of the cylinder 95 connects to the auxiliary reservoir through the boss 130 when the triple is worked as automatic air. While the portion of the cylinder 95 between the piston and the wall 107, under the same conditions, constitutes the train pipe pressure chamber. Under' the second cycle of operation, that is, when the triple is arranged for Hstraight air", that portion of the cylindcr 95 between the piston 96 and the wall 107 then becomes the main reservoir pressure chamber, while the cylinder 115 and coacting part of the cylinder 95 become the brake cylinder pressure chamber.

The head of the bushing 109 is greater Ain diameter than the tube 101, and this projecting portion of the bushing 109 engages the emergency slide valve 110. This slide valve 116 is a rectangular member with a flat base, and the cylinder or chamber 115 has a straight rectangular groove 117 cut throughout its length to receive the valve 116. The upper side of the valve 116 is made con :ave on an arc of slightly greater radius than the inclined circle of the tube 101. In the center of the valve 116 there is formed a cylindrical segment 118 on a curve slightly greater than 9 the curve of the head of the bushing 109, and the inside length of this segment 118 is as much greater than the thickness of the head of the said bushing 109 (say approximately three times) as is needed for the purpose ol the valve, as will ap] ar in due course. The head olIv the bushing 109 is thus so related to the valve that it may have a limited inovement and then carries the valve withv it.

l Cast in the valve 116 is a conduit 119 ending in two machined ports either square or rectangular. For clearness of illustration, the ports are indicated in Fig. 6 as square, but, in practice, rectangular ports of narrow width are preferred. These ports exactly match similar ports 120 and 121, machined or otherwise produced in the bottom of the groove 1.17 and in the central line thereof. The port 120 opens into a conduit 122 which leads to a chamber 123 (see Fig. (i) in the slow release cylinder 124, to be hereinafter described. As will appear further on, this conduit 122 constitutes the brake cylinder exhaust. The Aport 121 opens into a conduit 125 which connects with the service conduit 126 leading to the port 114 and also opening into another conduit 127, which latter leads into a threaded boss 128 for receiving a pipe leading to the brake cylinder or cyl inders, as the case may be.

The cylinder or chamber 115 is connected by a conduit 129 opening ultimately into a threaded boss y130 for receiving a pipe leading to the auxiliary reservoir. Tnterposed in the conduit 129 is a valve 131 so arranged that it 'may close the conduit 129, thus destroying the connection between the chamber 115 and the auxiliary air reservoir. As shown in Fig. 5, however, the parts are in position for the triple to operate with automatic air, as will hereinafter appear. rl`he exterior view of this valve 131 is shown in Fig. 12, where it will be'seen that it is provided with an operating lever 132.

In Fig. 5 the triple is shown in the release position. In this position the feed groove 133 places the cylinders 95 and 115 in communication one with the other, but only at this position and no other. The feed groove 133 is cut into the walls of the cylinder 95 and is of suiiicient area to charge up the auxiliary reservoir and chamber 115 to full train pipe pressure in about twenty seconds.

NOW, in the air brake equipments in common use, the feed grooves in the triples are generally adjusted to charge up the auxiliaries in seventy seconds. When the engineman places his valve on release, and thus admits main reservoir pressure to release the brakes, (considering the usualair brake systems) the triple piston is driven to the release position by the train pressure which has been restored to the regular pressure of seventy pounds bythe main reservoir. The feed groove in the triple is thus uncovered and the depleted auxiliary pressure, lowered by the air used in the brake cylinder, is gradually brought to train pipe pressure through the said feed groove. In the meantime, the main reservoir pressure is kept up to or near ninety pounds by the pump.

Y Now, f it is evidently advantageous to charge up the-auxiliaries as soon as possible, since a brake application may be needed at any time and the low auxiliary pressure will result in less braking effect if the application is emergency, or a greater train pipe reduc-I tion if the application 1s a service one. For instance, a full emergency application will give only a Vservice application f more or less pressure atv the brake shoes because of low auxiliary pressure, especially if a heavy serviceapplication immediately precedes the emergency application. If, again, the feed grooves` be made large, then the main reservoir pressure is drawn into the trainpipe f faster than the pump can furnish air, so that if a brake application is then made there would be insufficient pressure to release with, and theengineman would have to lap his valve Vand wait for the pump to bring up the main reservoirfpressure. Y 1

With the. system forming the subject-matter of the present application, the feed groove 'may be made as large as desired, since there are sixty pounds excess pressure though it is applied as usual. SI therefore arrange the feed grooves to charge up the auxiliaries in twenty seconds, which is more than three times as fast as in the ordinary brakes, and

will, probably, meet all practical requirements, but if, in practice, it becomes desirable to increase the speed of recharging, this may safely be done without bringing about the troubles mentioned. The feed groove 133 may be placed in communication with the cylinder or chamber 115 through a hole 134 drilled through the fiange of the piston 96, or the feed groove may be continued directly into the chamber 115.

Now consider the piston 135, which piston has a peripheral groove 136. This piston is located in a chamber 137 and is normally urged toward one end thereof by a light helical spring 138 of suflicient tension only to keep the piston normally in the position shown in Fig. 5. Leading from the cylinder or chamber 137 is a short cylindrical passage 139 in which moves a slide valve 140 in 'a groove similar to the groove 117 above referred to.

The passage 139 opensinto a chamber 141 which is in direct communication with the threaded boss-142 into which is screwed a pi e leading from the regular slide valve feed va ve, if one be used, which valve in turn is connected to the main reservoir. Such slide valve feed valve serves to reduce the pressure from the main reservoir of my system to a suitable pressure for use in mechanisms comprised in the system as a whole, but having nothing to do with the present invention, is not shown in the drawings.

Leading from the chamber 141 is a conduit 143 which ends at 144 where it is formed into a valve seat. Since this conduit is never used in connection with the automatic air system, it will not be further considered until the operation of the triple under the straight air conditions is set forth.

One end of the cylinder or chamber 137 is coincident with the edge of the casting 90 and is there counterbored to receive a disk 145 -provided with a central hollow boss 146 into which projects a piston rod 147 fast on the piston 135. The other side of the disk 145 has an inwardly-extending pin which forms one pole of the solenoid 148."

The hollow boss 146 acts as a guide for the piston 135, and the spring 138 finds an abutment against the disk 145. In the casting 91 in line with the chamber 137 there is formed y lchamber containing the solenoid 148 terminates in an integral diaphragm 151 on the other side of which there is formed another chamber 152. Leading from the chamber 137 to the chamber 152 is a small conduit 1531. The solenoid 148 has an armature 153 extending through the diaphragm 151 and entering the chamber 152 where it is provided with an end flange 154 between which and the diaphragm there is confined a light spiral spring 155. On the end of the armature 1.53 there is formed a valve 1.56 adapted to a valve seat 157 formed in a bushing 158 screwed centrally into one end of a cylinder 1.59 which, in turn, is screwed into the end of the chamber 152, as indicates. The outer' end oi' the cylinder 159 is closed tight by a screw plug 1.60 formed with a polygonal head 161 for the application of a wrench, which head is protected by a cap 162 screwed onto the plug and operating as a lock nut. This construction also admits of proper' regulation of the spring 169 and thereby the air pressure. Near the other end of the cylinder 159 there is formed an annular shoulder 163 against which is conned a rubber or elastic metallic (iliaphragm 164 by means of a locking ring 165. Guided within the interior of this locking ring is a head 166 bearing against the corresponding face of the diaphragm 164 and formed with a central pin extension 167 the free end of which enters a central recess 168 in the corresponding face of the plug 1.60. Surrounding the pin 167 between the head 166 and the plug 160 is a helical spring 169. The face of the annular shoulder 163 remote from that engaged by the diaphragm 1.64 is made tapering, and seated in this tapering shoulder face is a disk 170 formed with a central seat for a valve 171 having a stem extension 17 2 extending through the disk 17() into engagement with the diaphragm 164. 0n the other side oll the valve 171 there is another valve stem 173 terminating in a slightly rounded. head 174 entering a central bore 175 in the solenoid armature 153 and engaging a spring 176 housed in said bore.

As will hereinafter appear, the solenoid 148 is always energized except for service lap, and emergency applications. Consequently7 except under the three conditions named, the spring 155 is compressed and the valve 156 is 'withdrawn from its seat in the bushing The spring 169 is su'liiciently heavy and strong to normally keep the diaphragm. 164 in a position to open the valve 171, unless resisted by air in the chamber' 152 of a certain pressure.

Now, let it be assumed that there is no air in the brake equipment and hence none in the triple. The heavy spring 169 keeps the valve 171 open. This spring exerts a pressure of seventy pounds on the diaphragm, if the latter has a surface oi one square inch, and proportionately greater or less if the area of the diaphragm be greater or less than one square inch. Suppose that the main reservoir pressure, which may range anywhere from ninety to one hundred and ii'fty pounds, as before explained, enters the chamber 141. The piston 135 will be forced to move against the light spring 138, and the valve 14() participates in this movement. Normally this valve closes a port 177 and when the conipressed air enters the chamber 141, this port is opened wide as the valve 140 moves with the piston 135. There is, however, a leak around the piston 135 into the chamber 137 and by conduit 1531 into chamber 152, thence da hraffm.

by the valve 156, the solenoid 148 being energized, thence by valve 171 through the valve seat in the disk 170 into the space between this disk and the diaphragm 164, the disk being spaced a short distance from said Now, this space between the disk 170 and diaphragm 164 is connected by a conduit 178 to the chamber or cylinder 95 adjacent to the wall 107. Therefore, the air which has leaked by the piston 135 ultiA mately iinds its way into the cylinder 95.

The port 177 communicates with a conduit 179 which in the position of the parts shown in Fig. 5 is in communication with one branch 181 of the passages tluough a threeway valve 182 suitably mounted in the casing section 90. Another port 183 of this valve is in communication with a conduit 184 leading into the chamber or cylinder 95. Anothei port or passage-way 185 of this valve is in communication through a conduit 186 with a chamber 187 formed in the casing and in communication with a boss 188 into which is screwed the train pipe. This chamber 187 constitutes a water drainage chamber and has an opening at its lower end normally closed by a screw plug 189. 1n the meantime, the air in quantity has been flowing through the port 1.77 and the conduit 179 to the valve 182 where a portion follows the conduit 184 into the cylinder or chamber 95, and the other portion ilows through the conduit 186 into the drainage chamber 1.87, and ultimately into the drain pipe, which has a tee connection from which the train pipe eX- tends to the two ends of the car (considering but one car) where the usual angle cocks and hose are connected on. Under the present conditions, it is assumed that both anglo cocks 'are closed. Itis to be understood that in my system, considered as an electric system, no hose connections are provided., but still 1 provide, or may provide, the regular hose connections in order that this triple constructed in accordance with my invention may work in the usual train systems in common use.

The pressure rises rapidly in the several conduits and chambers named. As soon as the pressure reaches seventy pounds, the pressure in the space in 'front of the diaphragm 164 balances the tension of' the spring 169, and the diaphragm moving against this s ring the valve 171 follows under the impu se of the spring 176 until this valve iinally seats in the disk 170, thereby closing communication between the chamber 137 and the cylinder or chamber 95. N ow, the air, which has been leaking by the piston 135, rapidly equalizes with the air in the chamber 141, and with equal pressure on.

each side of it, the piston 134 being free to move under the tension of spring 138 takes up the position shown in Fig. 5, where the port 177 is closed. This movement is prompt and air is now at seventy pounds pressure in the train pipe and cylinder 95. Now, let the pressure be reduced below seventy pounds, The spring 169 opens the valve 171, and the pressure in the chamber 137 is quickly reduced to the pressure in front of the diaphragm 164. The piston 135 then again opens the port 177 until the pressure again reaches seventy pounds in the chamber 95,

thus seventy pounds pressure is constantly maintained.

The construction, both electrical and mechanical, of all the solenoids in the triple valve are identical, but the valves operated by them are somewhat different. Now, consider the emergency solenoid 190 and its armature 191. The solenoid 190 is housed in a suitable chamber formed -in the casting section 90, and this chamber has its end coincident with the edge of the casting counterbored to receive a disk 192 which is packed and secured by a packing ring 199 similar to the manner of packing and securing the disk 145 already referred to. However, the disk 192 is thicker than the disk 145 and has formed in it a peripheral groove 194 of semicircular cross section of considerable size.

This disk has a central passage for the armature 191, and drilled radially through the disk from the bottom of the groove 194 to the central hole is a passage 195 terminating in a port 196 leading to that face of the disk away from the solenoid. Formed in the casting section 91 in line with the solenoid 190 is a chamber 197, and within this chamber the armature 191. is expanded into a disklike head 198 in which is formed an annular groove on the face contiguous to the disk 192 in which is seated. a packing ring 193 proj ecting a distance from the face of the disk, so that when this packing ring isin engagement with the face of the disk, there is formed a small chamber 200 into which the port 1.96 leads. The outer face of the head 198 is formed with a central valve seat 201 which is in communication with the chamber 200 through a conduit 202formed in the head 198 and armature 191. The passage 195 in the disk 192 is in constant commu- 'solenoid 204 which constitutes what T may term the service solenoid.y This solenoid, 204, is held in the chamber provided for it by a screw plug 205 on the exterior of which is formed a polygonal head 206 for the application of a wrench. Leading from the solenoid 204 to the chamber 197 -is a smaller cylindrical passage 207 into which extends one end of the armature 208 of the solenoid 204. The outer end of this armature 208 is threaded to receive a cap'nut 209 the end wall of which is centrally perforated and terminates in a peripheral iange 210. The nut 209 is of such exterior diameter as to lit snugly but freely in the passage 207, and surrounding the nut 209 between the flange 210 and the corresponding end wall of the chamber 197 is a spring 211. Extending through the central perforation of the end wall of the nut 209 is a stem 212, expanded into a head 213 within the nut and exterior thereto, and at the other end of the stem expanded into a conical head 214 constituting a valve adapted to be seated in the valve seat 201. A helical spring 215 surrounds the stem 212 between the head 214 and the end wall of the nut 209., The chamber 197 is in communication with the atmosphere by a constantly open port 216. The purpose of the spring 211 is to project the armature 208 a certain amount, which is determined by the resistance of the spring 215 which, however, is weaker than the spring 211, and both are light springs. The spring 211 has but little extensibility `and at the position shown in the drawing it is supposed to have reached the limit of its extension and is only under such compression as may be produced by the lighter spring 215 which is always under a moderately strong tension. Under these circumstances, there is always su'llicient space between the head 213 of the stem 212 and the bottom of the hole in the screw cap 209 to insure a snug seating of the valve head 214. The recoil of the spring 215 is such as to place the spring 211 under only enough tension to hold the armature 208 securely in position, as shown, and the valve 214 likewise. There is considerable space between the face of the head 213 and the threaded end of the service armature 208. Of course, the springs put a like strain upon the emergency solenoid armature 191 as they do on the service armature 208. However, the emergency solenoid is. energized except when the controller for the valve, that is the triple valve as a whole, is put` in the emergency position. Therefore, it follows that by virtue of the attraction of thesolenoid 190, its armature 191 will remain in the position shown with the one exception noted, thus keeping the packing ring or gasket 193, which is made of rubber, iirmly against the face of the disk 192, thus insuring an air tight rubber oint. The pull of the armature 191 and the tensoY sion of the springs 211 and 215 is resisted by the pressure of the air in the chamber 200, which pressure, while normally insufficient to do so, tends, however, to force the solenoid armature 191 in the direction to open the rubber joint by forcing the gasket 193 away from the face of the disk 192.

Referring now to Fig. 6. As has already been explained, the conduit 122 coming from the port.120 enters the chamber 123. This chamber' is within the casting section 90. rlhis chamber 123 communicates at one end with a larger chamber 217 concentric with the chamber 123. These two chambers are about the same length and respectively contain pistons 218 and 219 connected together by the piston rod 220. This piston rod extends past the piston 218, which is located near one end of the chamber 123 and at its extreme end is formed into a valve 221 which is adapted to seat in the valve seat 222 that opens directly into a boss 223 into which there is screwed the brake cylinder exhaust pipe, if retainers are used, but if such retainers are not used, then no pipe is present and the exhaust is direct to the atmosphere from the boss 223. A small hole 224 is drilled centrally in the rod 220 on'the idle side of the valve, 221 and communicates with a radial hole 225 in the rod 220 back of the valve 221. This uts the chamber 123 in communication witi the atmosphere, regardless of the position of the valve 221, whether open or closed. As to the relative areas of the conduit formed by the holes 224 and 225 and the valve opening, and the purposes, this will presently appear. The rod 220 extends beyond the piston 219 and acts as a stop for the pistons 218 and 219 by abutting against a disk 226 which is seated in the counterbored end of the chamber 217 with a packing ring 227 like the disks 145 and 192, before referred to. This disk 226 has a central hole through it formed into a valve seat on the end remote from the chamber 217, while the end of the piston rod adjacent to this disk is formed with a passage 228 similar to the combined passages 224 and 225 to prevent this end of the piston rod 220 from lapping the central hole in the disk 226.

Seated in the cylinder 124 before referred to, is the slow release solenoid 229. This cylinder is closed by a screw plug 230 like the screw plug 205 before referred to. This solenoid 229 has an' armature 231 assing through an integral diaphragm 232 forming the base of the cylinder 124. This diaphragm is spaced from the disk 226 to form a chamber 233, which chamber is in constant communication with the conduit 122 by a port 234. The end of the armature 231 within the chamber 233 terminates in an annular flange 23 5 between which and the corresponding wall of the diaphragm or web 232 there is confined a helical spring 236. .Beyond the flange 235 the armature is formed with an extension constituting a valve 237 adapted to seat in the valve seat formed in the disk 226. The spring 236 is a light spring designed to keep the valve 237 seated when the solenoid 229 is denergized. The chamberforincd between the two pistons 218 and 219 is in free lcommunication with the atmosphere by a port 23S.

In line with the conduit `143 before referred to, there is formed in the casing ser tion a chamber' 239, and in line with this chamber is formed another larger chamber in which is housed a solenoid. 240 which l may term the straight air lap solenoid. The end of the chamber containing the solenoid 240 is closed by a screw pluO 241 similar to the screw plug 205 before referred to. This solenoid 240 has an armature 242 entering the chamber 239 and there expanded into an annular head 243 fitting the chamber and acting as a guide for the corresponding end of the armature. Between the head 243 and the corresponding end of the solenoid, the armature is surrounded by a helical spring 244, opposing the pull of the solenoid.. On the outer end of the armature there is formed a valve 245 adapted to the valve seat 144 at the end of the conduit 1.43, and when the solenoid is not active, the spring 244 maintains this valve closed. Leading from the chamber 239 there is a conduit 246 opening into the cylinder 95.

The conduit 179, beforereferred to, has a branch 247 which may be connected by valve 182 to another conduit 248 leading aroin'id. the chamber and opening into the chamber 115, as indicated at 249.

Branched off from the conduit 178 is another conduit 250 in the path of a bridging 1 recess 251 in the periphery of the valve 1.31, so that when the said. valve is properly turned, the branch conduit 250 is coupled up to another conduit 252 opening into another cylinder 253 alongside of the cylinder 159. This last-named cylinder 253 is screwed into a chamber 297 like the chamber 152 before referred to, and also receives at its inner en d a bushing 298 like the bushing 15S of the other cylinder, except that the bushing 298 has no valve seat formed in it. The cylinder 253 is provided with a tapered disk 299 held in place by the bushing 298, and with a valve 300 like the valve 171 of the cylinder 159. The cylinder 253 has a diaphragm 301 held in place by a locking ring 302 within which travels a head 303 on a pin or stein 304`entering a recess 305 in a screw plug 306 closing the outer end of the cylinder and protected by a cap 307, all like the similar parts in the cylinder 159. The pin 304 is surrounded by a spring 303 similar to the spring 169, except that it is adjusted to yield at a pressure exceeding fifty pounds per square inch, which is about the pressure an auxiliary reservoir 

